You did not put the options but I assume that one of them is that the value of the car decreases linearly over time. You can see from the equation that the 24000 is the cost of the car. Every year the car value is reduced by 93%. The t represents the number of years the car has been owned. however the equation is a bit flawed. It it really should be
y =24000 - 24000 (.07)t.
that way the car has full value at the 0 year owned. if you plugged the 0 year,in the given equation it would be worth nothing when purchased. the equation I gave gives the 24000 starting value and subtracts the 7% value loss for each year. They are similar burn guess in your equation it should state that it is only when t > 0. i don't know though that is just nitpicking
